In Japanese legend they are known as The Kamikaze — the divine winds — a reference to two mighty typhoons placed providentially seven years apart which, in the 13th century, destroyed two separate Mongol invasion fleets so large they were not eclipsed until the D-Day landings of World War II.

Marine archaeologists now say they have uncovered the remains of a ship from the second fleet in 1281 — believed to have comprised 4,400 vessels — a meter below the seabed, in 25 meters of water off the coast of Nagasaki, Japan.

Scientists are hoping they will be able to recreate the complete Yuan Dynasty vessel from Kublai Khan’s lost fleet using a 12-meter-long section of keel. The Mongols ruled China from 1271 to 1368.

According to Yoshifumi Ikeda, a professor of archaeology at Okinawa’s University of the Ryukyus, and head of the research team, the section could go a long way to helping researchers identify all the characteristics of the 20-meter warship.

“This discovery was of major importance for our research,” Ikeda told a news conference. “We are planning to expand search efforts and find further information that can help us restore the whole ship.”

Discovered using ultrasound equipment, the research team says it is the first wreck from the period to have an intact hull, the planks of which are still attached to the keel with nails.

Scientists say its good state of preservation — they were even able to establish that the planks were originally painted a whitish-gray — is due to the fact it has been covered by sand.

“I believe we will be able to understand more about shipbuilding skills at the time as well as the actual situation of exchanges in East Asia,” Ikeda told reporters in Nagasaki.

More than 4,000 artifacts, including ceramic shards, bricks used for ballast, cannonballs and stone anchors have been found in the vicinity of the wreck, linking it to the Yuan Dynasty invasion fleet.

Ikeda said there were no immediate plans to salvage the hull and the first step was to conserve the find by covering the sites with nets.

The Kamikaze — perhaps better known as the nickname given to the Japanese suicide pilots of the Pacific War — were a nation-defining event for Japan and set the limits of Mongol expansion in the east.

Historians say the first Chinese attempt to invade Japan in 1274 ended in disaster.

Having initially engaged a numerically superior Japanese samurai force at the Battle of Bun’ei in First Battle of Hakata Bay, the Chinese retreated to their fleet of 300 ships and some 500 smaller craft after just one day of battle on land. A typhoon destroyed a third of the fleet that night and the remnants limped back to port in Korea which was then a vassal state of China.

Seven years later, Kublai Khan amassed an impressive armada of 4,400 ships carrying 40,000 Korean, Mongol and Chinese troops in a bid to finally subjugate Japan. The Japanese, convinced of a second invasion, had spent the intervening years building strategic seawalls which made it difficult for the Chinese to land.

Unable to gain a beachhead after initially taking the island of Iki and Tsushima, the fleet was decimated by a two-day typhoon that hit the Tsushima Straits.

It is believed about 80% of the fleet was destroyed and the Khan’s troops either drowned at sea or slaughtered on the beaches by samurai.

The Vikings, the famed Scandinavian warriors, started raiding Ireland in 795 and plundered it for decades, before establishing two Irish outposts, according to the Annals of Ulster, a 15th century account of medieval Ireland. One outpost, Dúbh Linn, became Dublin, the other, Linn Duchaill, was lost in time. Perhaps until now. A team of archaeologists announced on Friday that it has found the lost Viking settlement near the village of Annagassan, 70 kilometers north of Dublin. “We are unbelievably delighted,” said archaeologist and team leader, Mark Clinton, an independent archaeological consultant.

The Annagassan locals have long believed they lived near an ancient Viking town or fort. The stories of Viking raids were told to local children by schoolteachers, and there were also occasional finds that underscored this story. For example, a few years ago, a set of handcuffs once used to shackle Viking slaves was found by a farmer ploughing land. The modern search for Linn Duchaill began 5 years ago when a local filmmaker named Ruth Cassidy, a member of the Annagassan and District Historical Society, enlisted the help of Clinton, a family friend, to find the lost Viking town. They searched through 2005, 2006, and 2007 and were on the point of despair when they came across a flat area—ideal for lifting boats out of the water for shipbuilding and repairs—a couple of kilometers up the River Glyde. They managed to secure funding to pay for a geophysicist, John Nicholls, to survey the site. Nicholls found a series of defensive ditches about 4 meters deep, running in lines. The pattern of ditches does not seem compatible with the typical Irish structure of the period, a ring fort, and no evidence of a Norman settlement, such as moat or castle remains, was found. That left just one other option: Vikings.

Despite this evidence, the researchers struggled to secure funding for excavation work. But the local Louth County Museum eventually offered funds to excavate at three locations. The team found 200 objects in 3 weeks, convincing them that they had found a major Viking shipbuilding town. There is evidence of impressive engineering, with an artificial island constructed out of the landscape to offer protection from attacks by the indigenous Irish. There is evidence of carpentry, smelting, and ship repair, with ship rivets dotted around the site. These features alone would make the site significant as few Viking longphorts—or shipbuilding towns—have been excavated. The team also found hacked coins, which Clinton says were a typical “calling card” of the Vikings, but there is also a total absence of pottery—the Vikings used wooden bowls. There are “high status” early Christian objects, too, probably stolen from the Irish.

Other Viking experts are cautiously optimistic that the long-lost Viking outpost has been found but emphasize the settlement needs to be solidly dated before the case is closed. “If the settlement found can be identified as Linn Duchaill, its value for linking archaeology to the written sources is very important,” says Peter Pentz, an archaeologist at the National Museum of Denmark in Copenhagen. “In addition, it appears that the site is almost untouched by later activity, unlike those of Dublin—some longphorts developed into urban settlements—and thus it might provide important knowledge of this particular type of settlement.”

“It’s really, really exciting,” adds Christina Lee of the University of Nottingham in the United Kingdom, an expert in Viking studies of Ireland and Britain. “I’m looking forward to hearing about the finds and the dating of the finds. It’s a really important step in thinking about the westward expansion of the Vikings, and the importance that Ireland had for the Viking world is something that hasn’t been recognized. Ireland in the Viking age is of strategic importance.”

One lingering question is why Linn Duchaill was abandoned while Dublin thrived. One theory is that because Dublin has better 24-hour access to the sea, it meant that the Vikings there could take to their ships and head out when they were under attack. At Linn Duchaill, tidal fluctuations would cut off access for several hours a day.